1. Field of the invention
This invention relates to a color image processing apparatus and method having the function of transmitting or receiving a color original.
2. Description of the Related Art
Conventional facsimiles used in facsimile communication, which has long been put into practical use, can transmit and receive only monochromatic (black-and-white) images. Accordingly, a facsimile communication circuit (abbreviated hereinafter a "circuit") network has of course been laid for the purpose of dealing with monochromatic images.
Recently, however, demands for color facsimiles have appeared. Although various kinds of methods are being studied and developed in various fields, the stage has not yet come wherein the methods are normalized and generally utilized, but they are now being internationally investigated. It is relatively easy in principle to configure a color fascimile. However, since almost all facsimiles currently used are for monochromatic images, even if some facsimile stations adopt color facsimiles, the picture quality of reproduced images is substantially deteriorated if most facsimiles installed at parties for transmission (the reception sides) are for monochromatic images, and so mutual communication becomes impossible. As a result, utilization of the current, i.e. monochromatic, circuit becomes impossible if some countermeasures are not taken. Accordingly, development of a method in which color facsimiles can be used while utilizing the current circuit without modification has been strongly demanded.
Techniques for discriminating whether an original has a black-and-white image or a color image are described in U.S. Pat. No. 4,739,397 and U.S. Pat. No. 4,953,013. There is room for improvement, however, in the above-described techniques from the viewpoint of transmission of color originals and black-and-white originals.